Plant derived vs horse urine estrogens and their effectiveness

I am 47 years old and had two "large masses" (not cancer) removed from my reproductive organs resulting in a complete hysterictomy May 2005. I tried Premarin 0.625 following the surgery and did not like the effects at all. I was then prescribed Ogen 1.25 and have taken it as prescribed for the past nine months. I continue to have severe nightsweats (drenched in sweat) and was wondering if I should consider speaking with my doctor about <u>increasing the mg amount of estropipate or request another trial of Premarin.</u> Originally, I was horrified to find out that Premarin came from horse urine and was more comfortable with Ogen because it was created from plants. <u>Is Premarin more effective regarding nightsweats than Ogen? Are some people more sensitive to animal derived estrogens than plant derived estrogens?</u> I have an appointment with my GYN February 27th and would like to have a base of knowledge prior to speaking with him about these issues. Thank you for your assistance.